Method for controlling engine during malfunction of coolant temperature sensor

• US 6,283,092 B1
• Filed: 12/27/1999
• Issued: 09/04/2001
• Est. Priority Date: 04/13/1999
• Status: Expired due to Fees

• Current Assignee: Hyundai Motor Company (Hyundai Motor Group)
• Original Assignee: Hyundai Motor Company (Hyundai Motor Group)
• Inventors: Jung, Chul-Hwa
• Primary Examiner(s): Dolinar, Andrew M.
• Application Number:
  US09/472,773
• Time in Patent Office: 617 Days
• Field of Search: 123/339.15, 123/359, 123/406.13, 123/479, 701/107, 701/113, 701/114, 374/1, 374/145
• US Class Current: 123/339.15
• CPC Class Codes: F01P 11/16 concerning coolant temperature F01P11/20 takes precedence
• CPC Class Codes: F01P 2025/13 Ambient temperature
• CPC Class Codes: F02D 41/222 relating to the failure of sensors or parameter detection devices
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

Disclosed is a method for controlling an engine during the malfunctioning of a coolant temperature sensor. The method includes the steps of determining whether the coolant temperature sensor is malfunctioning by using information supplied from various elements of a vehicle operation sensor; determining whether the engine is stalled when the coolant temperature sensor is malfunctioning; setting an initial value of information on the coolant temperature as a target value when the engine is stalled, and determining whether a start mode is canceled when the engine is determined to he operating; determining whether an air temperature sensor (ATS) is malfunctioning when the start mode is not canceled; setting, when the ATS is outputting information normally, the information on the air temperature as a target value, and performing addition and subtraction operations on the initial value of information and updating and learning the initial value of information with new information until the initial value of information reaches the target value of information; and outputting an engine control signal according to newly learned information on the coolant temperature, and when the newly learned information reaches the target value of information, terminating the updating of the initial value of information, and outputting an engine control signal to start the engine and to control idling of the engine after the engine is started by using the target value of information as the final learned information on the coolant temperature.

Claims

1. A method for controlling an engine during the malfunctioning of a coolant temperature sensor, comprising the steps of:

determining whether the coolant temperature sensor is malfunctioning by using information on temperature of coolant supplied from the coolant temperature sensor, information on intake air supplied from an air temperature sensor, information on engine rpm supplied from an ignition coil, information about on and off states of an ignition switch supplied from an ignition switch sensor, and information about a throttle valve opening supplied from a throttle valve switch;

determining whether the engine is stalled when the coolant temperature sensor is determined to be malfunctioning;

setting, when the engine is determined to be not stalled, an initial value of information on the coolant temperature as a target value of information on the coolant temperature and determining whether a start mode is canceled, the target value of information on the coolant temperature being previously established by a predetermined value in preparation for the engine being stalled;

determining whether the air temperature sensor is malfunctioning when the start mode is not canceled;

setting, when the air temperature sensor is outputting information normally, the information on the air temperature as a target value of information on the air temperature and performing addition and subtraction operations on the initial value of information on the coolant temperature and updating and learning the initial value of information on the coolant temperature with new information on the coolant temperature until the initial value of information on the coolant temperature reaches the target value of information on the coolant temperature; and

outputting an engine control signal according to newly learned information on the coolant temperature, and when the newly learned information on the coolant temperature reaches the target value of information on the coolant temperature, terminating the updating of the initial value of information on the coolant temperature, and outputting an engine control signal to start the engine and to control idling of the engine after the engine is started by using the target value of information on the coolant temperature as the final learned information on the coolant temperature.

2. The method of claim 1, wherein the method comprises the steps of:

setting, when the coolant temperature sensor and the air temperature sensor are out of order, the initial value of information on the coolant temperature with an initial value that is set in the event the engine is stalled, setting the target value of information on the coolant temperature with a target value of the air temperature that is set when the air temperature sensor is out of order, performing addition and subtraction operations on the initial value of information on the coolant temperature until the initial value of information on the coolant temperature reaches the target value of information on the coolant temperature, and updating the initial value of information on the coolant temperature with new information on the coolant temperature, and learning the updated result; and

outputting an engine control signal according to new information on the coolant temperature, and when the newly learned information on the coolant temperature reaches the target value of information on the coolant temperature, terminating the updating of the initial value of information on the coolant temperature, and setting the target value of information on the coolant temperature as a final learned information on the coolant temperature arid outputting an engine control signal to start the engine and control idling of the engine after the engine is started.

3. The method of claim 1, wherein the method comprises the steps of:

determining, when a start mode is canceled, that the starting of the engine is finished, setting the target value of information on the coolant temperature with the target value of information on the coolant temperature after the starting of the engine is finished, performing addition and subtraction operations on the finally learned information on the coolant temperature at the time the engine is started until the finally learned information on the coolant temperature reaches the target value of information on the coolant temperature after the starting of the engine is finished, and updating the information on the coolant temperature with respect to a predetermined time and performing a re-learning operation; and

outputting an engine control signal according to the updated and re-learned information on the coolant temperature, and when the relearned information on the coolant temperature reaches the target value of information on the coolant temperature, terminating the updating of the initial value of information on the coolant temperature, setting the target value of information on the coolant temperature as the finally learned information on the coolant temperature, and outputting an engine control signal to control idling after the engine is started.

4. The method of claim 1, wherein the method comprises the step of:

setting, when the engine is stalled, the target value of information on the coolant temperature with the target value of information on the coolant temperature that is set when the engine is stalled, outputting an engine control signal, and when the ignition switch, manipulated by a driver, is turned off because the engine is stalled, terminating all the control operations.

5. A method for controlling an engine during the malfunctioning of a coolant temperature sensor, comprising the steps of:

determining whether the coolant temperature sensor is malfunctioning based on information on the temperature of coolant supplied from the coolant temperature sensor, on information on intake air supplied from an air temperature sensor, on information on engine rpm supplied from an ignition coil, on information about on and off states of an ignition switch supplied from an ignition switch sensor, and on information about a throttle valve opening supplied from a throttle valve switch;

determining whether the engine is stalled when the coolant temperature sensor is determined to be malfunctioning;

if the engine is not stalled, setting an initial value of information on the coolant temperature as a target value of information on the coolant temperature and determining whether a start mode is canceled, wherein the target value of information on the coolant temperature is pre-set;

if the start mode is not cancelled, determining whether the air temperature sensor is malfunctioning;

if the air sensor is operating normally, setting the information on the air temperature as a target value of information on the air temperature, and performing addition and subtraction operations on the initial value of information on the coolant temperature and updating the initial value of information on the coolant temperature with new information on the coolant temperature until the initial value of information on the coolant temperature reaches the target value of information on the coolant temperature; and

outputting an engine control signal according to newly updated information on the coolant temperature, and when the newly updated information on the coolant temperature reaches the target value of information on the coolant temperature, terminating the updating of the initial value of information on the coolant temperature, and outputting an engine control signal to start the engine and to control idling of the engine after the engine is started by using the target value of information on the coolant temperature as the final updated information on the coolant temperature.

6. The method of claim 5, wherein the target value of information on the coolant temperature is pre-set in anticipation of the engine stalling.